1. The Field of the Invention
The present invention is directed to chip scale package manufacturing. More specifically, the present invention is directed to methods and apparatuses used to transport multiple chips on a unitary substrate through chip scale package manufacturing equipment using lead frame handling equipment that contacts indexing holes on the substrate so as to index the substrate through the chip scale package manufacturing equipment.
2. The Relevant Technology
Chip scale packages or chip size packages are microchip packaging arrangements that are slightly larger than the microchip itself, on the order to 1.2 to about 1.3 times the size of the chip or smaller. A chip scale package may also be the same size as the die itself. As illustrated in FIG. 1, a chip scale package 10 includes a rigid substrate 14 having therethrough a plurality of electrically conductive vias 22, seen in phantom that electrically connect to solder balls 16 on a bottom surface 17 of substrate 14. A chip or die 12, such as a memory chip, is located on a top surface 15 of substrate 14 and is wire-bonded by wire bonds 20 to bond pads 18 which are electrically connected to solder balls 16 through vias 22. As such, die 12 is electrically connected to solder balls 16 through vias 22. Once the appropriate interconnections are in place, an encapsulant 82, seen in phantom, is used to encapsulate die 12 and connections thereto to protect the same.
Existing automated equipment used in chip packaging, such as die attach and wire-bonders, are designed to accommodate lead frames. Lead frame compatible equipment, however, is not capable of accommodating chip scale package fabrication. As a result, chip scale package components are individually transported through chip scale package fabrication equipment in trays or boats where the components are held in place. Each tray or boat is usually in the form of a stamped metal tray or pocket. Typically, there is only one die and substrate therefor in a corresponding one tray or boat. As such, the assembly of chip scale packages in individual boats or trays is slow, tedious and expensive.
Alternatively, chip scale packaging equipment can be specifically designed to mass produce chip scale packages. Specifically designed chip scale packaging equipment is an efficient yet expensive way to produce chip scale packages. It would be a cost saving advantage to be able to fabricate chip scale packages without specifically designed chip scale packaging equipment by using existing equipment.
In accordance with the invention as embodied and broadly described herein, methods for manufacturing a chip scale package and a substrate panel for accommodating a plurality of chip scale packages are provided. The substrate panel in the present invention comprises a top portion opposite a bottom portion, a plurality of vias extending therethrough providing an electrical interconnection through the substrate panel, and a plurality of indexing holes for indexing the substrate panel through manufacturing equipment. The substrate panel further comprises a plurality of conductive landings and a plurality of die attach areas on the top portion of the substrate panel.
During chip scale packaging, the substrate panel is moved by lead frame handling equipment through chip scale packaging equipment. The lead frame handling equipment moves the substrate panel by contacting the indexing hole on the substrate panel. The chip scale packaging equipment through which the lead frame handling equipment moves the substrate panel includes die attach, wire bonding, encapsulation, die singulation, and other such chip packaging equipment.
The die attach equipment attaches a plurality of dies to the substrate panel and the wire bonding equipment connects wire bonds to bonding pads on the substrate panel that are associated with respective dies. Before or after encapsulation, the chip scale packages on the substrate panel are singulated to form a plurality of separated individual chip scale packages.
Conductive contacts, such as solder balls, which are attached to the bottom portion of the substrate panel, can be formed on the substrate panel by the chip scale packaging equipment through which the lead frame handling equipment moves the substrate panel. Alternatively, the conductive contacts can be pre-attached to the substrate panel prior to being indexed by the lead frame handling equipment through the chip scale packaging equipment.
These and other features of the present invention will become more fully apparent from the following description and appended claims, or may be learned by the practice of the invention as set forth hereinafter.